#!/usr/bin/python

from subprocess import call
from subprocess import Popen, PIPE

## Run license generation
call('make license', shell=True)

## Git diff changes
p = Popen(['git', 'diff', '--name-only', 'LICENSE.md'], stdin=PIPE, stdout=PIPE, stderr=PIPE)
output, err = p.communicate(b"input data that is passed to subprocess' stdin")
if b"LICENSE.md" in output:
   raise ValueError("""An error ocurred while validating the license generation.
            Changes were detected to the license generation output
            but weren't commited. Run make license and
            commit the changeset to make this validation pass.""")